taylor



(Hommel.) s sheets-sheet 24 W. P. TAYLOR.

TELEPHONE SYSTEM. NoE 559,874. 'Patented May 12, 1896.

(No Model.) 3 SheetsSheet 3.

W. F. TAYLOR.

TELEPHONE SYSTEM. No. 559,874, Patented May 12, 1896.

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www WWW-MM UNrrso STATES Artnr Ormes.

WALTER l". TAYLOR, OF MONTREAL, CANADA, ASSIGNOR OF ONE-HALF "O LOUIS M.PINOLET, OF SAME PLACE.

TELEPHON E SYSTEM.

SPECIFICATION forming part of Letters Patent No. 559,874, dated May 12,1896.

Application filed August S. 1894:. Serial No. 519,393. YN@ model.)

To uit whom, t may concern: ln the drawings, l, 2, 3, Ll, and 5 are keysBe it known that l, WALTER F. TAYLOR, a having square shafts, whichslide in guides subject of the Queen of Great Britain, residb b',connected by the side pieces li, the ing at Montreal, in the Province ofQuebec, shafts, the guides, and the frame being made 5 5 3 Dominion ofCanada, have invented certain of an electrical conductor, such as ametal. new and useful Improvements in Telephone Pins C in the shafts bytheir action on the Systems, of which the following is a specifiguide Y)prevent the shafts from being pulled cation. out of their places in theguides and also My invention relates to improvements in limit thedistance which the keys can move 6o io telephone systems composed ofmore than out-ward. Spiral springs C'around the shafts two telephoneinstruments provided with terbear against the pins C and the guide b'and minals, each electrically connected with one by their tension tendto keep the keys in of the other instruments. A person at one theirnormal position with the pins in contact of the instruments cancommunicate with with the guide l). 65 i5 another person at any of theother instru- D D2 D3 D4 D5 are spring-terminals resting ments withoutthe intervention of a centralnormally against a bar (l of insulatingmatestation operator by elosin g a circuit through rial, which islocated between the ends of the the terminal on his instrument, which iselecshafts and the springs, so as to keep the trically connected withthe otherinstrument; springs in alinement and out of contact with 7o 2oThe object of my invention is to provide a the rends. of the shafts. Oneof the springsimple and convenient device for closing the terminals islocated in the path of each key, circuit through the terminals, whichdevice is D being in the path of key l, D2 in the path automaticallyreset when the conversation is of key?, and so on. A bar-terminalE, ofcon finished and the telephone-receivers hung ducting material, crossesthe paths of the 7 5 2 5 upon their hooks. spring-terminals D, beingseparated from the Referring to the drawings, which form a terminals bya short space, so that when one part of this specification, Figure lis atop of the keys which has been pushed in far view of the device. Fig. 2is a front view ol enough to cause the end of its shaft to make thesame. Fig. 3 is a section of the telephonecontact with the oppositespring-terminal is 8o 3o hook, showing the details of the pawl. Fig.pushed in farther to any predetermined dis- -i is a section of Fig. 2 onthe line X, looking tance the said spring-terminal will be broughttoward the tripdcver. Fig. 5 is a view of into contact with thebar-terminal. F F are Fig. el, showingthe spring-terminalpressed innotches near the ends of the shafts and in contact with the bar-terminalby the key. the upper sides thereof, the portions of the S5 35 Fig. C isa view of Fig. l, showing the catch shafts beyond the notches beingtapered to engaged with the notch in the key. Figs. '7 a point. v and 8are diagrams of the electrical circuits G is a catch, both ends of oneside being of a system with three telephone instruments. pivoted to theside pieces B. The other side, In Fig. 7 instrument No. l is representedas which' is free, rests normally by its weight oo 4o calling upinstrument No. 2, and Fig. S repupon the tapering ends of the shafts a,be-` resents the same instruments when afteryond the notches F, so thatits edge is lower' ward communicating together. than the edges of thenotches. Nhen one The drawings represent the invention as of the keys ispushed in a predetermined disapplied to a telephone system suitable fortance, the catch will engage with its notch 95 45 use in stores,factories, and other similar and prevent the spring C from returning theplaces, in which system one battery serves key to its normal position.rl`he catches and cach telephone instrument to ring the bell of thenotches must be so located relatively to another instrument to call upthe person one another that when a key is pushed in far there; but thoseversed in the art could easily enough for the catch to engage with itsnotch 10o 5o apply the device to other systems from the the end of itsshaft is in contact with the opinstructions herein contained. positespring-terminal, but the spring-tervend of the hook.

The upper arm is provided with a retractile spring j, which is so adjusted as to elevate the outer end of the hook when the receiver isremoved, and Awhen the receiver is replaced on the heel; its weightovercomes the tension of the spring and de#y presses the outerend of thehook.

the path of the shoulder yon the pawl.

l l A pawl; K, having a shoulder 7c, is pivoted to the outer On the hookis a'pin 7:. ini,

spring L, attached tothe hook, bears against the pawl, so as to keep itsshoulder normally in contact with the pin and keep the pawl in avertical position. 'armll of the lever are so located relatively to oneanother that the projection on the arm l is in the 'path of the pawl.

The'pawl and the upper The lower side i of the pawl slants so that itsslope corresponds with that oi? the end of the upper arm Il.` When theouter end of the telephone-hook is:` depressed, the lower end of thepawl is belowf the upper-'end of the arm Il.

On removing the telephone-receiver from.y the hoolrV the hook'iselevated andthe pawl in passing the projection t' engagesyieldinglytherewith, for the pressure between the pawly and theprojection is against the sprin g,which 'yields and allows the pawl topass the projection without moving the lever. lVhen the hook isdepressed by the replacing of the receiver, the pawl engagesunyieldingly with` the projection and pushes upper arm of the lever toone side, for the pressure between the projection and the pawl isagainst the pin 7c', which prevents the pawl from moving by its action,on the shoulder 7c. This movement causesv t-helever to turn on itspivot and raises the lower arm, which in turn raises the free side ofthe catch G above the edges of the notches F. Thus any key whose notchwas engaged with the catch is released and is returned toits normalposition by the spring O".

Theelectrical circuits are as follows, referring particularlyto Figs. f7and 8: l and 2 are two telephone instruments. As the apparatus at eachtelephone instrument is a duplicate of that at the other instruments,but two lare shown for simplicity. In each of the instruments, l is atelephone-transmitter, m is an induction-,coil having the terminals m'miete its secondary coil, n is a local battery, and'p is aselfLinterruptinig electro-magnetic bell, which serves as an electriccall for the instrument. It is `immaterial whether a single receiver beused for speaking and hearing or a regular telephone instrumentcomprising a transmitter, a receiver, and an electric call; but as thelatter arrangement is usually the best the device or invention isrepresented as applied to a system containing such telephoneinstruments.

T R S S? S3 are electrical conductors, of which T serves `as areturn-conductor for all the telephones of the system. Branch electricalconductors lead from the main conductors to the telephone instruments.Provision is made by conductor S3 for connection with a thirdinstrument, which is not represented for thereason above stated. t is anelectric generator or battery,"one pole of which is connectedelectrically with the bar-terminals E in each instrument and the otherpole with the return-conductor T.

One terminal of the electric call in each instrument is connected withthe return-corr ductor T, and the other terminal is connectedelectrically with the contact q, with which the telephone-hook makescontact when the hook is depressed by reason lof thetelephone-receiverbeing thereon. The telephone-hook in each instrumentis connected electrically with the particular wire for that instrument.For

example, the hook in instrument l is connected withconductor S', thehook in instrument 2 is similarly connected with conductor Si, and soon. Y

One terminal of the telephone-receiver in each instrument is connectedelectrically with the return-conductor T, and the other terminal isconnected with the terminal m2 of the secondary coil. The terminal'm ofthe secondary is connected electrically with the guides Z1 b' and inthis way with the keys, which are thus in circuit with their respectivetelephone instrument. The terminal m' of the secondary is also connectedwith the contact r. y

The primary of the induction-coil m, the transmitter l, and the localbattery a are included in a local circuit having two contacts r vr'.This circuit is normally open at the contacts; but when thetelephone-hook is elevated by the removal of the receiver the twocontacts are electrically connected bythe hook and the circuit isclosed. One oi' the spring-terminals in each instrument is connectedwith a particular conductor. For example, all the terminals D areconnected with conductor S and thus with instrument l, the terminals D2are connected with conductor S2 and thus with instrument 2, and so on,the other terminals being connected with a particular instrument. Thereis no springterminal in instrument l connected with conductor S, nor inany of the other instruments is there a spring-terminal connected withthe conductor for that particular instrument, for such a terminal wouldbe useless, as it is obvious no one would desire to call up his owninstrument.

The operation of communicating between two instruments is as follows:Suppose, for example, a person at instrument No. l wishes IOO IIO

to speak with some one at instrument 2. presses in as far as it will gokey 2 on his instrument. The shaft of this key presses thespring-terminal D2 against the bar-terminalE and thus establishes acurrent through the electric call p in instrument 2. The current causesthe bell to ring and notifies the person there that some one desires tospeak with him. The current which has been established has the followingcourse: from the positive pole of the battery t along conductor R to theterminal barv E, through the spring-terminal D2, conductor S2, to andthrough the electric call thence back to the negative pole of thebattery by the conductor T. On removing pressure from the key 2 thelspiral spring C' moves the end of the key-shaft away from the terminalbar E till the further movement of the key is stopped by the engagementof the catch G with the notch F in the key-shaft. The above-describedcircuit through the electric call is thus opened and the bell stopsringing; but the spring terminal still remains in contact with the endof the keyshait.

lVhen the persons at both instruments remove the receivers from thetelephone-hooks J, the hooks are raised by the springs j and move oitthe contacts q and onto the contacts r and r'. This opens the circuitsthrough the electric calls and closes the local transmitter circuit, andalso connects the terminal m of Jthe secondary with the telephone-hook.A circuit for talking between instruments l and 2 is thus established,as follows: starting from m of the secondary coil of instrument l, ihrough the guides b h', key 2, sprin g-terminal D2, conductor S2,telephone-hook J, contact fr, to and through. the secondary coil ofinstrument 2, thence through .its telephone-receiver O to thereturn-conductor T, through the receiver O in instrument l, and thenceto the other terminal m2 of the secondary coil in instrument l, fromwhich the circuit was iirst traced. When the conversation is iinishedand the receivers are hung upon their hooks, the conscqu ent depressionof thehooks causes the pawl on each hook to turn the triplever and thusraises the lower end H of the lever. The lower end of the lever in turnlifts the catch G out of the notch in the key 2 with which it had beenengaged. The key is thus released and returned to its normal position bythe action ot the spiral spring C'. At the same time the spring-terminalD2 resumes its normal position against the insulating-bar CZ and out ofContact with the key. The depression of thc telephone-hook also opensthe circuits through the contacts r r and'restablishes the circuitthrough the electric call.

I claim as my invention l. A telephone system comprising telephoneinstruments included in circuits between a retiun-coiuluctor and a setof spring-terminals, each instrument being connected to a separatespring-terminal; a generator of electricity, one pole of which isconnected with the return-conductor and the other pole with abar-terminal in open-cirrcuitV relation with the set ofspring-terminals; and a telephone instrument included in a circuitbetween the return-conductor and a set of normally open circuit-closingkeys, having a separate key for each spring-terminal of the set, thespringterminals being so located that a key when moved from its normalposition closes successively the circuits between the said key and aspring-terminal of the set and between the said spring-termin al and thebar-terminal which is connected with the generator of electricity, andelectric calls in circuits which are normally open between thebar-terminals and the spring-terminals.

2. In a telephone system, the combination of movable keys provided withsprings whose tension keeps them in their normal position;spring-terminals, one located in the path of each key which is normallyout of contact with the said terminal; a bar-terminal crossing the pathsof the spring-terminals; a catch which engages with the keys when theyare in contact with the spring-terminals and the spring-ter1ninals arenot in contact with the bar-terminal; means for disengaging the catchfrom the keys; a telephone instrument in circuit with the keys and areturncon ductor; other telephone instruments in circuit with thereturn-conductor and the springterminals, each instrument beingconnected to one of the terminals; and an electric generator, one poleof which is connected electrically with the return-conductor and theother pole with the bar-terminal, and electric calls in circuits whichare normally open between the bar-terminal and the spring-terminals.

3. In a telephone system, the combination of movable keys provided withsprings whose tension keeps them in their normal position;spring-terminals, one located in the path of each key which is normallyout of contact with the said terminal; a banterminal crossing the pathsof the spring-terminals; a catch which engages with the keys when theyare in contact with the spring-terminals and thel spring-terminals arenot in contact with the bar-terminals; a lever connected with atelephone-hook and adapted to disengage the catch from the keys when thehook is depressed; a telephone instrument in circuit with the keys and areturn-conductor whose telephone-hook operates the lever for disengaging the said catch from the said keys; other telephone instruments incircuit with the return-conductor and the spring-terminals, eachinstrument being connected to one of the terminals and an electricgenerator, one pole of which is connected electrically with thereturn-conductor and the other pole with the bar-terminal, and electriccalls in circuits which are normally open between the bar-terminal andthe spring-terminals.

4. In a telephone system7 the combina-tion IOO IIO

of telephone instruments, included in circuits telephone `instrumentyincluded l:in theici'rcuit vwith springs which tend to keepthem intheir'normal positions -and having Aa separate key "the said- Spring-termilial and `the bar-terminal of [movablc'keys provided withspringswhose? lbetween a return #conductor and a set ofspring-terminals, each instrument being connected to aseparatespring-terminal; :a generator'of electricity, one pole of lwhichis connected with the return -conductor Aand the other pole with a'bar-terminalin open-circuit relation with the set of spring-terminals;a

between the :return-conductor and a Aset v'of normally opencircuit-'closing keys provided for each spring-'terminal of -theset, thespringterminals being-so located 'that -a key when moved from its normalposition :closes -successively the circuits between the said key and aspring-te'rminalof the set and between Whichis connecte'dwith-thevgenerator of-electricity; and "a catch yadapted Ato engage'with,andjretain any -key which is ymoved into the position lin which itcloses l`tlie'circuitbetween i itself and a spring-terminal `rof thefset, electric calls in circuits which are normally?openbetweenithefbar-termin'aland the springterminals.

5. In atelephone system the=combination 'of Etelephone instrumentsincluded Vin circuitg between a return-conductor and a set of;spring-terminals, eachinstrument ibeingf connected to-aseparate'spring-terminal; a genv lcrater-of electricity,one'pole-ofwhichisfcon- 'nected with the return -fconductor and Itheotherpole with'a-bar-termina'l in open-circuit@ relation with -the setof spring-terminals; ai telephone `instrument Iincluded 1in -a circuitibetween the return-'conductor and asetoty normally open circuit-closingkeysprovided with springs which tend to keep them in their.

sively the circuits'betwee'n the said key and a spring-terminal-of theset-and betweenthe said spring-terminal land the 'bar-'terminal which isconnected with the generator of electricity; 'a catch adapted to engagewith and retain 'any'key that is movedinto theposition in which itlcloses the circuitfbetweenitself and a spring-terminalof the set;andmean's for automatically disengagin'g -the catchffroml the lkeysafter a conversation isiinis'hedfcon-iy sisting of a movable hook and alever whereby the movement*ofthe-hook when the receiverof Athe telephone-in circuit'with the keysli's placed thereon `moves vthe catch-outofen-i 'gagement with the keys, and electric call'sin;

circuits which are normally open between the bar-terminalfand thespring-terminals. 6. In a telephone system, the combination tensionkeeps them fin their normalposition ;i

jterminals, lone -'located in the patho'ffeach keys when theylare movedvinto contact with the terminals; iafpivoted leveradapted-to disengagethe catch ffrom the keys when caused to turnen its pivot; a 'telephoneLinstrument having a pawl on its hook which, when the hook is depressed,engages -unyieldi-ngly with 'the lever 1and causes it to turn and whenthe hook iselevated engages yieldinglytherewith, the said 'instrumentbein g in :circuit with the keysfanda return-conductor; and othertelcphone instrumentslineircuitwith the returnconductor andthe'terrninals, each instrument beingconnected to 'fone of jtheterminals.

l7. [n a telephone system, the combination ofls'liding keys, providedwith springs lwhose -tension Ykeeps them 2in their normal position landhaving shafts with notchestherein, the shafts f'beyondfthe notches beingtapered; ter- 1minals,eac'h in circuit with a separate4telephoneiins'trument and located in xthe vpat-h of 'oneof the keyswhich is normally outof contact with the said terminal; -a pivoted catchwhose ffree -side Irests normally upon the tapered parts-of fthe-shafts,`but which engages with the notches when the keys are moved solthat the 'shafts are Sin contactiwiththe terminals; a pivoted leverf-having an upper anda Ilower arm; the lower arm being under the freeside o'ff'the catch and the upper arm 'bein g provided with-aprojection; and a telephone instrument having a telephone-hook with afpawl thereon which, when the hook vis de- 1'pressedfengagesunyieldingly with the projectionandpushesftheupper arm of the'lever Atoone iside and, when lthe'hookis elevated, `engages `yieldinglytherewith.

58. iIna-telephone system, -the combination of 'movable keys;spring-terminals, one located in thelpa'th of 'each keyand normally in'open-circuit relation therewith; means for keeping Athespring-terminals in alinement consisting Vof an insulating-bar locatedbetweenfthekeys andthe said terminals; a telc- `phone instrumentlincluded in a circuit between-'the'keys anda return-conductor; andother telephone instruments included in-cirlcuitsbetweenthereturn-conductor and the -spring-terminals, `each telephonebeing connected-to a separateterminal.

9. In atelep'hone system,the combination of movable keys;spring-terminals, one located-in the path of=each key; abar-terminallorossing the 'paths ofthe spring-terminals; a `telephone instrument inlcircuit with-the keys and-a'return-conductor; other telephoneinstruments in circuit with the-return-conduc- 'tor and thespring-terminals, each instrument being connected to one ofthe'terminals 'and-having' an electric call in its circuit; and anelectric generator, lone-pole of which is 5 electrically connected withthe return-conductor and the other pole with the bar-terminal.

10. lIn a telephone system of any number "of stations and having anelectric call an'd telephone at each station, electric generators `forthe electric circuits ofthe calls and teleroo IOS

phones, swing-terminals at each station, and a bar-terminal in the pathof the spring-ten minals for closing the circuits of the electric calls,when the springs are brought in contact with the bar, and key-terminalsmovable to and from the spring-terminals, the said keys and springsbeing in circuit with the telephones, and circuitclosers governed by thetelephones for opening and closing the circuits thereof.

1l. In a telephone System of several stations, a switchboard at eachstation both for calling another station and effecting telephoniecommunication therewith, consisting,` of terminals movable to and fro,spring-ter-

